U.S. patent number 5,249,574 [Application Number 07/812,427] was granted by the patent office on 1993-10-05 for implantation of leads.
This patent grant is currently assigned to Ventritex, Inc.. Invention is credited to Mary E. Bush, Eric S. Fain.
United States Patent |
5,249,574 |
Bush , et al. |
* October 5, 1993 |
Implantation of leads
Abstract
A lead or other member may be implanted into the body, and
typically at the heart, by a method which comprises and following:
inserting one of a pair of pivotally attached jaws of an attachment
tool through a hole in a body membrane, particularly the parietal
pericardium surrounding the pericardial cavity. The other of the
pivotally related jaws is placed outside of the body membrane in a
position of registry with the first of the jaws. The jaws carry an
attachment member which is to be attached for securance to the body
membrane. The jaws are brought together in pressing relation with
the membrane and attachment member positioned between the jaws, to
cause attachment of the attachment member to the membrane. The lead
may be pre-attached, or subsequently attached, to the attachment
member after the above process steps.
Inventors: |
Bush; Mary E. (Fremont, CA),
Fain; Eric S. (Menlo Park, CA) |
Assignee: |
Ventritex, Inc. (Sunnyvale,
CA)
|
[*] Notice: |
The portion of the term of this patent
subsequent to July 7, 2009 has been disclaimed. |
Family
ID: |
27093779 |
Appl.
No.: |
07/812,427 |
Filed: |
December 23, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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641500 |
Jan 15, 1991 |
5127421 |
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Current U.S.
Class: |
607/9; 128/898;
607/126 |
Current CPC
Class: |
A61N
1/0587 (20130101) |
Current International
Class: |
A61N
1/05 (20060101); A61N 001/05 () |
Field of
Search: |
;128/785,419P,898 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Brochure by the Dritz Corporation-one page. .
Article by Dixon et al. from Laboratory
Investigation-Defibrillation, vol. 76, No. 5, Nov., 1987, pp.
1176-1184 Entitled: Improved Defibrillation Thresholds With Large
Contoured Epicardial Electrodes and Biphasic Waveforms..
|
Primary Examiner: Kamm; William E.
Assistant Examiner: Getzow; Scott M.
Attorney, Agent or Firm: Mitchell; Steven M. Meltzer; Mark
J.
Parent Case Text
CROSS REFERENCE TO RELATED CASE
This is a continuation-in-part of application Ser. No. 641,500,
filed Jan. 15, 1991, now U.S. Pat. No. 5,127,421.
Claims
That which is claimed is:
1. A method of implanting in the body an implantable member, which
comprises:
inserting a first of a pair of pivotally attached jaws of an
attachment tool through a hole in a tissue membrane while placing
the other of said pivotally attached jaws outside of the tissue
membrane in a position of registry with the first of said jaws,
said jaws carrying an attachment member which is attached to said
implantable member and is adapted for securance to the tissue
membrane; and bringing said jaws together in pressing relation,
with the tissue membrane and the attachment member positioned
between said jaws, to cause attachment of said attachment member to
the tissue membrane for securance of said implantable member
thereto; and disconnecting said jaws from the attachment member and
said implantable member.
2. The method of claim 1 in which each of said jaws carries an
interconnecting portion of said attachment member, each
interconnecting portion being proportioned for mating engagement
with the other portion upon the application of pressure of said
jaws with said interconnecting portions and the tissue membrane
positioned between said jaws.
3. The method of claim 1 in which said implantable member is a
lead, said lead being attached to the attachment member at a
position outside of the parietal pericardium.
4. A method of implanting in the body an implantable member, which
comprises:
inserting one of a pair of pivotally attached jaws of an attachment
tool through a hole in a tissue membrane, while placing the other
of said pivotally related jaws outside of the tissue membrane in a
position of registry with the first of said jaws, said jaws
carrying an attachment member which is to be attached for securance
to said tissue membrane; and bringing said jaws together in
pressing relation, with the tissue membrane and the attachment
member positioned between said jaws, to cause attachment of said
attachment member to the tissue membrane; and thereafter attaching
said implantable member to said attachment member and disconnecting
said jaws from the attachment member.
5. The method of claim 4 in which said implantable member is a lead
which defines a distal electrode that carries means for securing
said lead to said attachment member.
6. The method of claim 5 in which said securing means is carried on
a flexible tab carried on said electrode.
7. A method of claim 5 in which said electrode comprises a flexible
patch, said means for securing being carried on said patch.
8. A method of implanting a lead at the heart, the improvement
comprising:
inserting a first of a pair of pivotally attached jaws of an
attachment tool through a hole in the parietal pericardium
surrounding the pericardial cavity, while placing an opposed one of
said pivotally related jaws outside of the parietal pericardium in
a position of registry with the first of said jaws, and further
comprising implanting said lead at the heart including the step of
bringing said jaws together in pressing relation with the parietal
pericardium positioned between said jaws, to cause attachment of an
attachment member to the parietal pericardium, and thereafter
withdrawing said jaws.
9. The method of claim 8 in which, after said attachment member is
attached to the parietal pericardium, an electrode carried by said
lead is attached to said attachment member.
10. The method of claim 8 in which, after attachment of said
attachment member to the parietal pericardium, a connection member
which is attached to said lead is releasably attached to said
attachment member.
11. The method of claim 8 in which said attachment member comprises
two interlocking halves which are brought together by said closing
of said jaws with the parietal pericardium positioned between said
halves, one of said halves being attached to said lead.
12. The method of claim 11 in which said interlocking attachment
member halves are each releasably seated respectively in a
longitudinal slot defined in said first and opposed jaws, whereby
said halves are retained by said slots against motion transverse of
said jaws.
13. A method of implanting a lead in the body, which comprises:
inserting an attachment member connected to tether means through an
access site into the body; attaching said attachment member to a
tissue membrane, while said tether means extends from the
attachment member through the access site; and sliding a lead along
the tether member, beginning at the access site, through the
patient to cause a distal end of said lead to occupy a position
adjacent to the attachment member.
14. The method of claim 13 in which said lead is attached in a
position with its distal end adjacent the parietal pericardium.
15. The method of claim 13 in which said lead is tubular, said
tether means occupying the lumen of said lead as the lead is
advanced to a position where the distal end of the lead is adjacent
the attachment member.
16. The method of claim 13 in which said lead defines loop segments
through which said tether means extends to facilitate advancement
of said lead along the tether means to a position with a lead
distal end being adjacent the attachment member.
Description
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for permanently
implanting leads adjacent the heart, plus fixation devices for
holding implanted leads in desired positions anywhere in the body.
The term "leads" is intended to also include other implantable
fixtures besides electrical leads, such as fluid conduits,
reservoirs and the like.
It is well-known in the field of cardiology that ventricular
fibrillation can be effectively treated by the application of
electrical shocks to the heart. Such defibrillation may be achieved
by the application of electrical paddles to the chest of the
patient or directly to the heart tissue, if the chest is open
during surgery.
More recent improvements have lead to the development of
implantable defibrillators, which monitor the heart for arrhythmias
and automatically initiate defibrillation when fibrillation occurs.
Such devices often incorporate electrodes that are located on the
epicardium or parietal pericardium, being connected to a
defibrillation unit by means of a lead.
However, major surgery is generally necessary to implant and affix
present defibrillator lead systems into their desired position. For
example, a median sternotomy or lateral thoracotomy may be
required. Such procedures can be very traumatic to the patient, and
may have adverse side effects such as surgical complications,
morbidity, or even mortality. Candidates for such a procedure thus
may include only those persons for whom the potential benefits
outweigh the significant risks. Because of the significant surgical
risks of the present lead systems, many patients who might
otherwise benefit from the use of an implantable defibrillator are
excluded.
The issue of fixation of the lead into a desired position can be
important for any implantable device, but it is especially
important for defibrillator leads, since the electrodes of the
typical pair of defibrillator leads present cannot be allowed to
touch each other. When implanting paddle electrodes via sternotomy
or thoracotomy, there is adequate access of the leads and
surrounding tissues to suture the edges of the leads to those
tissues to fixate the leads in place. However, in the case of a
deployable lead that has been placed through a small incision, or a
paddle electrode placed through a small incision using a limited
surgery technique, suturing by hand is not possible due to the lack
of access and the lack of visibility. A deployable lead is a lead
that is inserted into its position in a transversely collapsed
configuration, with the electrodes being then allowed to expand
outwardly into a new, laterally expanded configuration which is
typically larger than the incision providing entry of the lead into
its desired position.
Another difficulty involved in fixating leads to the epicardium,
when compared to fixating leads to the endocardium, relates to the
lack of trabeculae for engagement with tines, and also the presence
of coronary blood vessels that must be avoided if one attempts to
use screws or hooks that penetrate the tissue.
By this invention, a lead is preferably attached to the parietal
pericardium, and not the epicardium. Thus there is practically no
possibility of rupturing coronary vessels or of tearing myocardium.
Also, no endoscope, rigid or flexible, is required in order to
provide good fixation of the lead to the parietal pericardium. It
is possible to crimp a fixation device as described herein so that
no sharp edges of the device are exposed to tissue. Likewise, the
fixation device may be visible on x-ray and fluoroscopy, for
effective observation both during implantation and afterward.
Likewise, fixation devices as described herein may be attached
firmly, yet relatively atraumatically, since only fibrous tissue is
penetrated and gripped. Thus there is essentially no possibility of
puncturing the pleura, and the pericardium remains intact.
The lead may be removed by coring the parietal pericardium, or the
lead may be removed by snapping its fixation device apart, while
the lead is held by snapping the fixation device together. Also,
the fixation device for the lead can be made so unobtrusive that an
abandoned fastener can be left attached to the parietal pericardium
and a new one placed, if desired.
Thus, the invention of this application exhibits significant
advantages over prior art methods for implanting leads,
particularly adjacent the heart, as shown for example in Chin et
al. U.S. Pat. No. 4,865,037 or Person U.S. Pat. No. 3,999,555, for
example.
DESCRIPTION OF THE INVENTION
In accordance with this invention a method is provided for
implanting a fastener onto tissue and specifically a lead at the
heart, which comprises the following steps:
One inserts a first of a pair of pivotally attached jaws of an
attachment tool through a hole in a tissue membrane such as the
parietal pericardium surrounding the pericardial cavity, while
placing the other of said pivotally attached jaws outside of the
parietal pericardium or other tissue membrane in a position of
registry with the first of the jaws. The jaws typically carry an
attachment member which is adapted for securance to the parietal
pericardium or other tissue, and which is typically attached to a
lead, for example an electrically conductive lead, or if desired, a
tubular conduit lead for the administration of medication or other
fluids, or for drainage from areas adjacent to the tissue
membrane.
One then brings the jaws together in pressing relation, with the
parietal pericardium (or other tissue membrane) and the attachment
member positioned between the jaws, to cause attachment of the
attachment member to the parietal pericardium or other
membrane.
Following this, one disconnects the jaws from the attachment
member, and withdraws the jaws.
In some embodiments, each of the jaws may carry an interconnecting
portion of the attachment member, with each interconnecting portion
being proportioned for mating engagement with the other portion
upon the application of pressure of the jaws, with the
interconnecting portions and the parietal pericardium or other
membrane being positioned between the jaws. The lead, when present,
may connect with the attachment member at a position either inside
or outside of the parietal pericardium or other membrane.
As another embodiment, a lead or the like may be attached to the
attachment member after the attachment member has been placed onto
the parietal pericardium or other body membrane. This attachment
can take place either before or after disconnection of the jaws
from the attachment member.
The attachment member, or interlocking attachment member halves,
may be releasably seated in a longitudinal slot which is defined in
one or both of the jaws of the attachment tool. The longitudinal
slot or slots may be open at their distal ends, so that the
attachment member or halves thereof may be retained by the slots
against motion transverse of the jaws, but when the jaws are
withdrawn, the attachment member or its halves may slide distally
out of the slot to remain in the desired position.
In an additional embodiment, an attachment member, connected to
tether means, may be inserted through an access site into the body
and into the vicinity of the heart or other organ. The attachment
member may then be attached to the parietal pericardium or other
body membrane, while the tether means extends from the attachment
member and through the body to the access site of the patient. One
can then slide a lead, or other implantable medical device, along
the tether means, beginning at the access site, through the patient
to cause the distal end of the lead to occupy a position adjacent
to the attachment member. Thus the tether acts rather like a
catheter guidewire in facilitating the advancement of a lead, or
other medical device such as a catheter, to advance to a desired,
predetermined position.
The step of attaching a lead to a fastener member may take place
during manufacture, or before the surgical procedure begins, or
during the surgical procedure.
The lead used in the method of this invention may be of essentially
collapsed outer diameter while placed through the hole in the
parietal pericardium or other membrane. Then, after such placement,
portions of the lead may be laterally deployed outwardly within the
pericardial cavity. Examples of such outwardly deployable leads are
well known and of various types. The essentially collapsed outer
diameter may be provided in conventional manner by a sleeve outside
of a curved electrode or electrodes to hold then straight and
inwardly collapsed until the sleeve is removed at which time the
electrode assumes a new configuration having an enlarged lateral
dimension, as shown, for example in the cited Chin et al. U.S. Pat.
No. 4,865,037 and other prior art. See also Bush et al. application
Ser. No. 591,389, filed Oct. 1, 1990.
The tool used in accordance with this invention for securing leads
to a tissue site may comprise a pair of opposed, movable jaws for
applying compressive action to join together first and second
engaging parts of the attachment means, which parts are each
respectively and releasably carried on one of the jaws in opposed
relation. Such a tool may be generally conventionally manufactured
to accomplish this purpose, except as otherwise described
herein.
Preferably the first and second engaging parts of the attachment
means are of the interlocking variety so that they may be brought
together by the jaws, with a body organ portion such as the
parietal pericardium positioned between them, for releasable or
permanent interlocking engagement. One of the first and second
parts of the attachment means may then be attached to a lead, so
that the lead is secured to the body organ by this action.
Among other designs, the first part of the attachment means may
comprise a bead while the second part of the attachment means may
comprise a plate having a first aperture. The first aperture is
sized to allow the bead to be pressed through the aperture in
snap-fit relation by the compressive action between the opposed
jaws.
The plate is preferably made of a semi-flexible material having a
desired amount of resilience, so that the snap-fit relation may be
achieved with relative ease, yet the retention will be strong
enough for the desired purposes.
DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 6 are schematic views of various sequential steps
in the method of implanting and affixing a defibrillation electrode
lead into the pericardial cavity by attachment to the parietal
pericardium;
FIG. 7 is a detailed, elevational view, taken partly schematically,
illustrating substantially the step of FIG. 5 in greater
detail;
FIG. 8 shows details of a step subsequent to the step of FIG.
7;
FIG. 9 is an enlarged, perspective view of the plate which may
serve as one of the engaging parts of the fastener member used in
this invention;
FIGS. 10 and 11 are plan views of various designs of attachment
tools which may be used in accordance with this invention;
FIG. 12 illustrates another embodiment of the implantation of a
lead in accordance with this invention, in which the lead is
positioned outside of the parietal pericardium and is secured
thereto;
FIG. 13 provides a detailed view of the engaging parts of the
fastener member used in FIG. 12;
FIG. 14 is a plan view showing how an attachment loop and fastener
may be attached to a lead, particularly a paddle electrode, for use
in accordance with this invention;
FIG. 15 is a perspective view showing how a lead may be attached to
the parietal pericardium by attachment to an attachment member
part, which attachment member part is carried by one of a pair of
jaws of an attachment tool;
FIG. 16 is a generally schematic, elevational view showing a pair
of jaws applying a two-part attachment member to the parietal
pericardium;
FIG. 17 shows a step subsequent to that of FIG. 16, where the pair
of jaws apply a patch electrode on the outside of the parietal
pericardium to the mounted attachment member;
FIG. 18 is a plan view of a patch type electrode which carries a
distal tab, with a connector member for connection with an
attachment member carried on a body membrane such as the parietal
pericardium;
FIG. 19 is an enlarged, plan view of the surface of the distal end
of a jaw of an attachment tool, showing how an attachment member or
part thereof can be held therein;
FIGS. 20 and 21 are an enlarged, elevational views, taken
90.degree. from each other, showing how a ball-type attachment
member part, having an attached cord, can be retained by the jaw in
a slot thereof;
FIG. 22 is a schematic view showing the jaws of an attachment tool
carrying a ball and apertured plate-type attachment member part,
about to be attached to the parietal pericardium of the
patient;
FIG. 23 is a schematic view of a subsequent method step from that
of FIG. 22 in which the attachment tool is withdrawn, and a lead is
advanced along the tether carried by the ball-type attachment
member part so that the distal electrode of the lead may be
spontaneously advanced into position against the parietal
pericardium;
FIG. 24 shows a further step in the process illustrated by FIGS.
22-23; and
FIG. 25 shows a schematic view of a similar process in which the
orientation of the attachment member is reversed so that a lead can
be advanced along the tether into engagement with the outer surface
of the parietal pericardium.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Referring to the drawings, FIGS. 1 through 6 disclose various steps
in the method of implanting a lead at the heart, with FIGS. 7 and 8
showing details of the process. As shown in FIG. 1, a lead 10
comprises a lead body 12 having outwardly deployable electrodes 14,
which may be made of conductive metal. Lead body 12 and electrodes
14 are initially closed in an outer sheath 16, typically in a
manner as disclosed in Bush et al. U.S. application Ser. No.
591,389, filed Oct. 1, 1990 and entitled Multiple Electrode
Deployable Lead. Otherwise, any lead having outwardly deployable
electrodes may be used in this particular embodiment, with the
electrodes being held in essentially radially collapsed
configuration either by a sleeve or by one or more stylets.
Heart 18 of a patient is exposed by a surgical procedure, and an
aperture is formed in the parietal pericardium 20, so that access
to the pericardial cavity 22 is provided to lead 10.
As one modification to customary deployable electrode leads of the
prior art, lead 12 used herein carries a distally mounted loop 24
made of nylon suture material or the like. A magnified view of the
distal end of lead 10 is shown in FIG. 7. There, loop 24 is shown
being connected to a bead 26 which may be made of plastic, ceramic
or metal, and which comprises one of the engaging parts of the
fastening member used in this particular embodiment, as previously
described. Bead 26 is connected to the distal end of lead 10 by a
flexible member 28, typically a piece of multistrand cord or the
like for permanent securance of bead 26 to the distal end of lead
12. Also in FIG. 7, electrodes 14 are shown in their outwardly
deployed configuration after removal of sheath 16, particularly as
shown in FIG. 3.
A suture cord 30 is provided, extending along the length of lead 10
and passing through loop 24, with the cord then extending
rearwardly again along the length of lead 10. Typically, cord 30 is
more than double the length of lead 10 so that both of its rear
ends extend out of the incision site and the skin during the
surgical procedure.
After the aperture 19 has been made in the parietal pericardium 20,
the sheathed lead 10, and cord 30 are advanced through such
aperture as shown in FIG. 2, until the electrodes 14 of the lead
are positioned in the desired spot.
After such positioning takes place, as shown in FIG. 3, sheath or
sleeve 16 may be withdrawn. This allows spring electrodes 14 to
deploy outwardly as shown.
After removal of sheath 16, as shown in FIG. 4 an attachment tool
32, having opposed jaws 34, 36, is brought to bear, first by
threading at least one or preferably both of the lengths of cord 30
through an aperture 38 in jaw 34 of the attachment tool.
It can also be seen that the other jaw 36 of the attachment tool
carries a plate 40, which plate is held in position on jaw 36 by
suture cord 42 which extends typically the distance of attachment
tool 32, so that the proximal ends of cord 42 and also well outside
of the surgical incision used to gain access to the heart area.
The shape of plate 40 is more clearly shown in FIG. 9, in which
plate 40 comprises a central first aperture 41 and a pair of side
apertures 44. Cord 42 is shown to extend along the length of jaw
36, then passing underneath plate 40 to project upwardly through
one of the side apertures 44. A length 46 of the cord 42 then
extends transversely across the side of jaw 36 that is opposed to
the side that carries plate 40 in a jaw recess 48 (FIG. 7). The
cord 42 then passes downwardly through the other side aperture 44
and then extends rearwardly again along the jaw 36. Thus, plate 40
is temporarily retained in position as long as cord 42 is held
under tension.
Referring to FIGS. 4 and 5, jaw 34 of the attachment tool is then
passed into aperture 19, being guided by the passage of cord 30
through aperture 38 in jaw 34. Eventually, as shown in FIGS. 5, and
7 loop 24 extends through aperture 38, with flexible member 28
extending around the side or end of jaw 34 and bead 26 being seated
on aperture 38. Jaws 34, 36 of attachment tool 32 are positioned
adjacent an intact portion of the parietal pericardium, spaced from
aperture 19 as shown in FIGS. 5 and 7. Plate 40 is shown in FIG. 7
in section, with first aperture 41 being seen in section. A chamber
50 is provided in jaw 36 behind plate 40 and aperture 41.
Then, upon closing of jaws 34, 36, bead 26 may be pressed through
aperture 41 in snap-fit relation, with bead 26 fitting into chamber
50, and taking a section of flexible member 28 along with it. Plate
4 is flexible enough, and aperture 41 is sized, to allow this to
take place.
Then, each of cords 30 and 42 are pulled at one distal end to cause
the entire cord to be withdrawn from the area of jaws 34, 36 and
the attachment tool 32. The attachment tool itself may then be
withdrawn from the site, leaving the attached lead 12 in a
configuration as shown in FIGS. 6 and 8. Bead 26 is shown to be
retained on the side of the parietal pericardium 20 remote from
that side facing lead 10 by its snap-fit relation with plate 40.
Plate 40 is too large to penetrate through the parietal pericardium
20, even should the stretched portion thereof 52 surrounding bead
26 be broken or necrose.
Thus, flexible member 28 is securely anchored to provide secure
anchoring to lead 10. Because of this, outwardly deployed
electrodes 14 cannot migrate in an undesirable manner, so that a
second lead may be positioned at a different but relatively close
area of the heart, with good reliance that the respective
electrodes of the two leads will never touch.
As an advantage of the method of this invention, before affixation
of the lead, it is possible to move the lead around to test
defibrillation thresholds until a desirable defibrillation
threshold is obtained. Only then, if desired, can the steps
illustrated in FIGS. 4 through 8 be performed so that each lead
which is implanted in accordance with this invention can be
implanted with a high probability of effective performance.
Then, the aperture 19 in parietal pericardium 20 may be sutured
together to close the aperture down around lead 10 on all
sides.
Thus, a method is provided in which a lead may be implanted at a
desired position at the heart without need of visually observing
the deployed electrodes 14 and without seeing the exact attachment
site of the lead.
FIGS. 10 and 11 show two particular types of attachment tools which
may be used in accordance with this invention. The attachment tools
may be of the generally conventional design of analogous surgical
instruments except for the precise shapes of their jaws, which may
be as shown in FIG. 7, and as otherwise indicated in here.
As a specific, different modification, each of the respective jaws
34, 36 of FIG. 10 may carry tunnel means to position and house a
portion of the respective cords carried on the jaw and arm of the
tool. For example, jaw 36 of tool 54 defines tunnel members 56
through which cord 42 can extend, to hold the cord in a position
essentially parallel to the extent of jaw 36 and the corresponding
tool arm 36a.
Likewise, jaw 34 may carry one or more tunnel members 60 for the
same purpose, positioned along jaw 34 and in its corresponding arm
34a for control and retention of cord 30.
The attachment tool illustrated in FIG. 10 is particularly adapted
for emplacing leads at anterior heart positions.
Turning to FIG. 11, a similar emplacement tool is shown which may
function in a manner similar to that of the previous disclosure.
Specifically, the tool of FIG. 11 is adapted for emplacement of
leads at posterior heart positions. Apart from the difference in
shape of the tool in FIG. 11, it may function in a manner similar
to the tool of FIG. 10. Specifically, tunnel members 56a and 60a
may be provided for the retention of the respective cords which are
present for purposes described above.
Referring to FIG. 12, an alternate embodiment of attachment tool in
accordance with this invention is shown, in the process of
attaching a lead with a different retention system.
As before, the parietal pericardium 62 of the patient's heart 64 is
opened with an aperture 66, so that one jaw 67 of an attachment
tool 68 may be inserted. Another jaw 70 is positioned on the
outside of the parietal pericardium, and each of the jaws carries
an interengaging part 72, 74 of a fastener member.
As specifically shown in FIG. 13, part 74 of the fastener member
may comprise a ring which defines a plurality of prongs 76, while
part 72 of the fastener member defines another ring with a facing
annular groove 78. To make connection, the prongs of ring 77 fit
into the groove 78 of ring 79, and are retained there, in the
manner rather of the assembly of a clothing snap on a piece of
cloth, with the design being similar to such a conventional
clothing snap.
As shown in FIG. 12, lead 78 is carried in a sleeve 80, which may
be withdrawn to cause the electrodes at the distal end of lead 78
to expand outwardly in the conventional manner of a deployable lead
having one or more electrodes. The distal end of lead 78 is
connected to one end of a flexible member 82 such as a strong,
permanent surgical suture or the like, while the other end of
flexible member 82 is connected to fastener half 72.
Thus, the structure as illustrated in FIGS. 12 and 13 is analogous
to the previous embodiment, except that lead 7 is being emplaced
outside of the parietal pericardium 62 rather than the inside
thereof. When the two jaws are brought together by handle mechanism
84, with the parietal pericardium between them, the fastener member
halves 72, 74 are connected together in a permanent manner, if
desired, and lead 78 is thus permanently attached in a desired
position relative to the heart.
Sleeve 80 is withdrawn to deploy the electrodes of the lead, and
tool 68 is correspondingly withdrawn, leaving lead 78 behind.
Aperture 66 in the parietal pericardium is sutured, and the patient
is closed up.
Referring to FIG. 15, another method of securing of a lead 110
having a distal patch-type electrode 112 to the parietal
pericardium 114 is shown. An attachment tool having a pivotally
mounted pair of jaws 116, 118 is shown in which the distal end
portion of jaw 116 penetrates a hole 120 which has been cut in the
parietal pericardium. The distal end of jaw 116 carries a snap-type
fastener member 122, as previously described, for engagement with a
snap fastener member 124 which is attached to electrode 112.
Particularly, snap fastener member 124 may be attached to the woven
metal fabric of the patch electrode 112 by conventional gluing,
welding or the like. Thus, with a single closing motion, the
respective jaws 116, 118, can press snap fasteners 122, 124
together into snap-fit relation, to cause the securance of patch
electrode 112 to the parietal pericardium. It can be seen in this
particular embodiment that jaw 118 does not carry an attachment
member part, but is merely present to provide pressure.
Referring to FIG. 16, jaws 116a, 118a of a similar attachment tool
carry at their respective distal ends a pair of snap fasteners
122a, 124a similar to the previous embodiment, with jaw 116a
penetrating through hole 120 to be on the inside of the parietal
pericardium 114a. Jaws 116a and 118a may then be closed to cause
snap fasteners 122a, 124a to be brought together into snap-fit
relation on the parietal pericardium as in previous embodiments.
See for example FIG. 12, with the difference that no electrode or
lead is attached to either of snap-fasteners 122a, 124a.
Snap-fastener 122a may be temporarily attached to jaw 116a by a
projection 126 carried by fastener 122a and extending into a mating
recess of jaws 116a. Similarly, fastener half 124a may be
releasably carried on jaw 118a by a second projection 128 which
matingly fits into a corresponding recess in jaw 118a. Conversely,
the jaws may carry the projections and the fasteners the recesses,
to the same effect.
Projections 126, 128 and the corresponding recesses may be so
shaped that when the respective snap fasteners 122a, 124a are
brought together into snap-fit relation, the force required to
cause projections 126, 128 to be pulled out of their recesses in
jaws 116a, 118a is less than the force required to separate the
respective snap halves 122a, 124a from each other. Thus, after the
snap halves 122a, 124a are brought together into locked
relationship to form a complete snap 130 connector carried on the
parietal pericardium 114a (as in FIG. 17), jaws 116a, 118a may be
brought apart again, causing spontaneous separation of projections
126, 128 from their recesses. Then, jaws 116a, 118a may be removed,
if desired, until the subsequent step of FIG. 17 is to be
performed. Such projections can be used with the other embodiments
as well.
Referring to FIG. 17, a lead 110a and a connected, distal patch
electrode 112a are attached to snap connector 130.
Patch electrode 112a is shown to carry a third snap connector 124b,
which fits with projection 128 of snap connector 130. Specifically,
the overall design of such a snap system may resemble the
well-known clothing snaps, in which each mating snap on a separate
piece of fabric to be snapped together is made of a pair of
interlocked snaps. One of such a snap pair is analogous to snap
portions 122a, 124a. A third snap member 124b then may lack a
mating snap section, but may be attached to the patch electrode in
the manner of snap 124 of FIG. 15, and which snaps into engagement
with the pair of engaged snaps 130. This process is facilitated
once again by jaws 116a, 118a which press third snap 124b into
snapping engagement with the combined snaps 130, which comprise
snap portions 122a and 124a.
As another embodiment, FIG. 18 shows a lead 110b, having a patch
electrode 110c and a distal tab member 134, which carries a
connector part 136, capable of reversible snap-fit connection with
attachment member 130, which is carried on the parietal pericardium
114a, as shown in FIG. 17.
FIG. 19 shows an alternate jaw 118b of an attachment tool, which
otherwise may be similar to that shown previously. Jaw 118b defines
parallel, axial slots 140, open at the distal ends 142. An
attachment member part 124c can thus be retained in sliding
relation. Accordingly, attachment member part 124c can be
positioned by jaw 118b of the attachment tool to engage with
another, mating attachment member, with attachment member 124c
defining either an aperture or a projection as may be desired.
Then, after member 124c is mated with another attachment member on
the opposite side of the parietal pericardium as in previous
embodiments, it may be freed from its engagement with jaw 118b by
simply drawing jaw 118b proximally away, to cause member 124c to
slide out of distal end 142 of the respective slots 140, out of
engagement with jaw 118b. Thus, attachment member 124c, and a lead
or tether 144 to which it is optionally attached, may be implanted.
Also slots 140, 142 may carry any type of appropriate attachment
member.
FIGS. 20 and 21 show a jaw 116b of an attachment tool which may be
used in conjunction with jaw 118b of the same tool, if desired. Jaw
116b is adapted to carry generally a spherical bead 146 in a slot
148, with bead 146 being attached to a tether or cord 150. Bead 146
or any modification thereof may comprise part of an attachment
member which can engage with apertured attachment member 124c, to
be retained on the parietal pericardium in a manner similar to that
specifically illustrated in FIGS. 7-8.
Then, when attached, jaw 116b may be disengaged simply by sliding
the attachment tool proximally away, so that cord 150 slides
distally out the free end of slot 148, typically simultaneously as
attachment member 124c slides out of its respective slots 140.
Referring to FIG. 22 a step of another embodiment of this invention
is shown, in which the jaws 152, 154 of an attachment tool are used
as in previous embodiments to place attachment member parts 156,
158 onto the parietal pericardium 160. The attachment member which
comprises parts 156, 158 may be of the spherical bead and apertured
plate type, as shown in previous embodiments. Spherical bead 158
carries a tether or cord 162, with tether 162 extending from bead
158 back along the attachment tool and through an access site of
the body of the patient.
Then, as shown in FIG. 23, a lead 164 having multiple, arcuate
electrodes 166, is slidingly connected to tether 162 by means of
laterally positioned rings 168 through which tether 162 extends.
Catheter 164 may then be advanced along tether 162, in the manner
shown, or, if desired, in a tubular sleeve to straighten out the
respective electrodes 166 until after implantation at the proper
position, after which the sleeve may be withdrawn and the
electrodes 166 allowed to spring outwardly. Lead 164 is guided to
the proper position, with tether 162 functioning rather like a
guidewire for an angiography or an angioplasty catheter. This may
be applied to other lead designs as well.
Lead 164 can be advanced along tether 162 to a position of
substantially maximum advancement as shown in FIG. 24, in which the
distal end 170 and electrodes 166 are positioned within the
parietal pericardium 160, entering through aperture 153. Tether 162
can retain catheter 164 in the desired position for an indefinite
period of time. Also, lead 164 may be sutured to the parietal
pericardium adjacent aperture 153.
Referring to FIG. 25, a similar process can be performed, in which
an attachment member 176, comprising a mating bead and apertured
plate in a manner similar to previous embodiment, can be mounted on
the parietal pericardium 160 in the opposite direction from that
shown in the embodiment of FIGS. 22-24. Tether 162a extends
outwardly from the parietal pericardium 160 rather than inwardly as
in the previous figures. Thus, bead 164a may be advanced along
tether 162a to occupy a position closely adjacent to the exterior
of the parietal pericardium rather than the interior thereof.
Also, in this embodiment, lead 164a may define an internal lumen
178 and a side aperture 180 through which tether 162a may extend,
so that as lead 164a is advanced along tether 162a, at least a
portion of the tether occupies the internal lumen 178 rather than
rings 168 as in the previous embodiment.
If desired, the leads of this invention which are placed may be
replaced by catheters, or liquid transmitting leads rather than
electrical impulse transmitting leads, in any circumstance where
such a device is to be positioned and retained next to a body
membrane which is strong enough to carry an attachment member. The
parietal pericardium is made of dense fibrous connective tissue,
and is thus strong, and capable of retaining any of various designs
of attachment members, including the designs shown herein.
Thus, by this means and also by the previous embodiment, it is
possible to implant one or more leads at a position about the heart
or elsewhere, remote from the site of the surgery, well beyond
where suturing can take place. Significant advantages of the method
of implantation described above may also be achieved by this
embodiment of the invention as well as by the previous
embodiment.
Turning to FIG. 14, the distal end of a lead 90 is shown,
terminating in a conventional paddle electrode 92 formed of a mesh
of conductive wires and surrounded by a supporting cuff 94 which
contains a suturable fabric, rubber, or the like.
A member 96 is provided for securing an attachment loop and a
fastener onto a lead. Member 96 may be used with respect to paddle
electrode lead 90 or a deployable lead as disclosed in this
application, or any other appropriate type of lead.
Member 96 carries a needle 98 which may be used for suturing. A
suture 100 or equivalent cord is connected to the end of the
needle, and is of sufficient length to permit suturing or
attachment thereof by means of needle 98 to suture rim 94 or to any
other appropriate spot on typically the distal end of a deployable
or other type of lead.
At the end of cord 100 opposed to needle 98, an attachment bead 102
is provided, or any other desired attachment member. Attachment
bead 102 may be used in the manner previously described with
respect to attachment bead 26.
Then, cord loop 104 is also provided, which cord loop is intended
for use in the manner of loop 24 as previously discussed.
Accordingly, an attachment bead 102 and a cord loop 104 may be
attached to a large variety of leads by simple sewing action,
making use of cord 100 and needle 98. Then, when cord 100 has been
firmly attached to the lead, needle 98 may be cut away, to prepare
any desired lead for use in accordance with this invention.
The above has been offered for illustrative purposes only and is
not intended to limit the scope of the invention of this
application, which is as defined in the claims below.
* * * * *